<p>The behavior of subgrade soils with different water contents under freeze-thaw conditions is a significant factor to be considered in pavement engineering, since freeze-thaw cycles substantially affect deformation of subgrade under cyclic loading, which in turn influence the performance of pavements.<br /> In this study, the resilient modulus tests were performed on unfrozen silty clay before and after the first freeze-thaw cycle. Resilient modulus tests were carried out at various water contents including 5%, 8%, 10%, 12% and 15%. The behavior and response of the samples were monitored and recorded, and are compared through this report. In addition to resilient modulus tests, the accumulative deformation of the samples under cyclic loading was investigated. The results reveal that freeze-thaw cycles have the potential to have significant impact on permanent deformation of silty-clay under cyclic load.</p> / Master of Engineering (ME)

<p>The current Canadian masonry standard CSA S304.1 (2004) deals with the design of unreinforced and reinforced concrete masonry shear walls. The use of one or the other type of wall construction is limited to a particular seismic activity zone based on the seismic hazard index. The code does not provide any provisions for partially grouted shear walls in regions with moderate seismic demand. The experimental program described in the thesis focuses on the dynamic performance of partially grouted nominally reinforced concrete masonry shear walls having less steel and larger spacing than specified by the Canadian masonry standard for the minimum seismic requirements.</p> <p>A total of six reduced scale shear walls were designed and constructed to fail in flexure. A constant axial load was present throughout the test, which represented a single story building. The walls were grouped into three categories, Type I, II and III. Type I and III walls had reinforcement present only at the ends of the wall with vertical reinforcement ratios of 0.12% and 0.20%, respectively. Type II walls had an additional reinforcement located mid-length of the wall with a reinforcement ratio of 0.17%. Two identical walls were tested for each type with the exception of the Type III, where only one wall was tested. The walls were subject to dynamic loading of a scaled 1940 EI-Centro earthquake N-S component. The experimental results were evaluated and discussed pertaining to behaviour, lateral load capacity, stiffness, period, displacement ductility and load reduction factors.</p> <p>The general behaviour of the tested shear walls was dominated by rocking motion where a full length mortar joint crack developed, along with the yielding of reinforcement. The rocking motion was able to dissipate energy instead of the more common diagonal cracking and crushing of masonry. Type I and II walls had yields close the predicted values, while Type III wall had a lower yield point than predicted. All walls had similar trends of stiffuess degradation. The period increased by a factor of 2 or more during the course of testing. An idealized bilinear envelope was used to calculate the displacement ductility. It was found to be greater than 2 with load reduction factors ranging from 1.9 to 2.6.</p> <p>It was concluded that nominally reinforced partially grouted walls are potentially viable to be used in seismic zones where the seismic hazard index exceeds 0.35.</p> / Master of Applied Science (MASc)

<p>Reduced-scale models have become an attractive alternative to full-scale experimental laboratory testing due to both physical and fmandal restrictions. In order to have confidence in the ability of a reduced-scale model to replicate fullscale prototype behaviour, test data from reduced-scale research must be correlated and compared to test results of full-scale, prototype, materials. The overall goal of the following thesis is to provide a detailed comparison between third-scale models and full-scale prototype masonry materials, assemblages and wall components. The study includes a total of three phases of experimental testing. The first phase focuses on the individual elements that make up a reinforced concrete masonry shear wall. Elements examined include: third-scale model concrete blocks, mortar, grout and reinforcing steel. The second phase of the reseflrch project focuses on testing different configurations of masonry assemblages in an attempt to combine individual third-scale model elements into a composite assemblage to correlate behaviour to that ofpreviously tested full-scale<br />assemblages. The third and final phase of research compares two third-scale reinforced masonry shear walls to full-scale walls testing previously at McMaster University. In general, the third-scale model specimens showed good relation to full-scale prototypes for both the individual components and shear walls.</p> / Master of Applied Science (MASc)

<p>Concrete masonry blocks are widely used in North America and the world; however, production poses some environmental implications, specifically the depletion of natural resources and contribution to the release of carbon dioxide into the atmosphere. Accordingly, methods to improve the sustainability of the industry need to be developed. The replacement of cement with post -consumer waste glass powder and/or the replacement of fine aggregate with post-consumer waste polymer in the production of concrete blocks are proposed as potential options to reduce the environmental impact of block production while maintaining adequate block performance.<br /> The effect of using glass powder and polymers on the block and prism properties has been analyzed to determine the most effective implementation of these post-consumer waste materials. Physical properties, mechanical properties and alkali-silica reaction of the blocks and the mechanical properties of the prisms were tested. From the experimental program, it was determined that replacing Portland cement with waste glass powder up to 25% had no detrimental effect on the block and prism properties. Replacing the sand with polymer aggregate was found to have a detrimental impact on the strength of the block. The effect of adding up to 6% polymer aggregate as sand replacement on the prism mechanical properties was found to be minimal. The reduction in block compressive strength when polymer aggregates are used is attributed to the increase in the material's porosity.</p> / Master of Applied Science (MASc)

<p>To delay the onset of delamination and to ensure the CFRP continues to supply strength after initial delamination of reinforced concrete beams strengthened with near surface mounted CFRP bars, a new mechanical anchoring system was developed and tested in this investigation. The anchors were integrally connected to the CFRP bars and extracted from a proprietary product commonly known as NEFMAC. The anchored bars were installed by cutting grooves into the concrete cover, boring holes at anchor locations and using epoxy to bond the strengthening bars to the groove surfaces.<br /> <br /> A total of seven simply-supported reinforced concrete beams were tested in fourpoint bending to study the effectiveness of the proposed anchoring system. One beam served as a control specimen, two beams were strengthened with unanchored near surface mounted bars and the remaining four beams were strengthened with the anchored bars. As an exploratory study two of the four anchored beams were also strengthened with anchored near surface mounted CFRP transverse bars to determine if the system is an acceptable substitute for internal steel stirrups.<br /> <br /> Results of this study reveal that the anchors can delay delamination and after initial delamination, the anchored beams continued to carry the applied load whereas the unanchored beams lost strength immediately following concrete cover delamination. Although there was not a significant gain in flexural capacity in the anchored beams relative to the unanchored beams, the improved ductility provided by the new system shows promise. Further investigation is needed to determine the number of anchors needed, depth of penetration, size and location of such anchors to achieve composite behaviour between the strengthening bars and the reinforced concrete section.</p> / Master of Applied Science (MASc)

<p>From observations of increases in global average air and oceanic temperatures, melting of polar ice and significant increases in net anthropogenic radiative forcing, it is clear our global climate system is undergoing substantial warming (IPCC, 2007). A key area of concern for hydrologists and engineers alike is to determine how this warming will affect various hydrologic processes. To date, climate change impact studies have generally involved the downscaling of large-scale atmospheric predictors with the result then being input into a hydrological model to see how flow in a river/basin will change under various future climate change scenarios. Although many studies have been completed using large scale global climate model (GCM) data, few studies have shown the strength of regional climate models (RCM). In this work, a comparison between the effectiveness of using CRCM4.2 vs. CGCM3.1 data in a climate change impact study (climate forcing under the SRES A2 climate scenario) is considered. The study area is the Chute-du-Diable sub-basin located within the Saguenay-Lac-Saint-Jean Watershed in Quebec, Canada. Downscaled results are compared with observed meteorological data for the years 1961-1990 at the Chute-des-Passes (CDP) and Chute-du-Diable (CD D) weather stations; and flow is simulated in the Mistassibi River and the Chute-du-Diable reservoir. A regression technique (SDSM) and a dynamic artificial neural network model (Time lagged feed-forward neural network (TLFN)) are used for downscaling the CRCM4.2 and CGCM3.1 data, and the HBV2005 hydrological modeling system is used for simulating flows in the watershed. For the current period (1961-1990), downscaling results reveal that downscaled CRCM4.2 is closer to observed meteorological data at both CDD and CDP stations than downscaled CGCM3.1 is. The Wilcoxon Rank-Sum test and Levene test reveal that regardless of the climate model, both TLFN and SDSM are capable of capturing the monthly means and variance of precipitation and temperature. Statistical results reveal that TLFN is best for downscaling temperature and SDSM is best for downscaling precipitation. With respect to the future climate scenario, regardless of the climate model or the downscaling method, a 1 to 3 ° C increase in annual mean maximum temperature and a 1 to 4°C increase in annual mean minimum temperature are predicted for the 2050s future period. In the case for precipitation, the CRCM4.2 model shows increases in annual precipitation will vary from 1 to 7% in the 2050s regardless of the downscaling method used. The CGCM3.1 model on the other hand, shows increases in annual precipitation ranging from 15 to 23% regardless of the downscaling method employed. Additionally, simulations of river flows and reservoir inflows reveals significant changes in mean flow will occur as a result of the warming trend. Simulations show that for both SDSM and TLFN, CRCM4.2 and CGCM3.1 show an increase in river flow and reservoir flows throughout all seasons except for the summer where reduction of flow is observed. Annually, at the Chute-du-Diable reservoir mean flow changes vary from a 16-28% increase in the 2050s and at the Mistassibi River annual mean flow changes vary from a 12-62% increase. In all cases CGCM3.1 model shows a larger increasing trend than the CRCM4.2 model.</p> / Master of Applied Science (MASc)

<p>p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 11.5px Times}</p> <p>Pulsed Arc Electrohydraulic Discharge (PAED) is a direct plasma water treatmenttechnology that can generate physical and chemical reactions in a single unit process to treat a broad range of chemical and biological contaminants. Karpel Vel Leitner et al. (2005) demonstrated that PAED is capable of treating contaminants via the reduction</p> <p>mechanism, as they reduced nitrate to nitrite. Perchlorate is a difficult-to-treat contaminant with significant negative impacts on human health. One treatment approach for perchlorate is to reduce it. Therefore, laboratory experiments were designed and conducted to examine the efficacy of PAED for reduction of perchlorate in a water matrix.</p> <p>A 3L stainless steel cylindrical reactor with two titanium electrodes connected to a 0.3 kJ/pulse pulsed arc power supply was used for the treatment processes. Three sets of factorial experiments were performed to determine: a) the power supply settings and water matrix properities for optimal ozone and hydrogen peroxide production; b) the efficacy of PAED for the reduction of perchlorate; and c) the power supply settings and water matrix properties for optimal perchlorate reduction.</p> <p>The results of these experiments indicated that as much as 0.0544 mg/L of ozone was generated, with water conductivity and the presence of dissolved oxygen being the most important factors contributing to ozone generation. Hydrogen peroxide was not generated in detectable amounts under any of the conditions employed in these experiments. Finally, perchlorate was not reduced by detectable concentration in any of the conditions employed in these experiments.</p> / Master of Applied Science (MASc)

<p>The goal of seismic response modification is to elicit more favourable behaviour from structures during earthquakes. A popular means for this modification is through the use of energy dissipation devices (EDDs), which effectively lower the seismic demand on main structural components by absorbing a portion of the seismic input energy. This energy is often absorbed through the yielding of metallic components within these devices. Examples of traditionally used metals are steel and lead which exhibit bilinear hysteretic behaviour. The introduction of shape memory alloys (SMAs) into the realm of seismic energy dissipation has occurred fairly recently and has occurred in large part due to their exceptional characteristics for earthquake engineering applications, including hysteretic properties. SMAs exhibit flag-shaped hysteretic behaviour creating the potential for relatively simple yet effective EDDs.</p> <p>In this study, the non-linear time history analysis of 1, 2, 4, and 8 storey chevron-braced steel frame models was carried out using the program Ruaumoko^®. The braces in each frame were modelled to emulate EDDs exhibiting flag-shaped hysteresis. For comparison, the same frames were analyzed with braces modelled to emulate EDDs exhibiting bilinear behaviour with full hysteresis loops. Each frame was subjected to an ensemble of ground motions to determine their mean responses as measured by several response indices. A parametric approach was adopted to determine the effect of various parameters on response and the parameter values resulting in advantageous behaviour. Tension-compression (T-C) and tension-only (T-O) braces were studied to illustrate their effect on response as well. Pushover tests on the frames were also performed, using the program SAP2000^®, to help validate the results.</p> <p>The behaviour of the frames in this study was generally governed by the backbone curve of the brace hystereses defined by post-yielding stiffness parameter, α, normalized yield force, η, and normalized stiffness, θ. Increasing these parameters generally decreased interstorey drift, residual interstorey drift, column ductility demand, beam ductility demand, and absorbed energy. However, this also had the effect of increasing acceleration and base shear. The energy dissipation parameter, β, had little effect on response. In general, the responses of the frames with flag-shaped hysteretic braces, as measured by interstorey drift, column ductility demand, beam ductility demand, base shear, and absorbed energy, were very similar to those frames with the bilinear hysteretic braces - in both magnitude and trend. However, the frames with bilinear braces tended to have lower accelerations, and the frames with flag-shaped braces tended to have lower residual drifts. The T-C braces were generally more effective than the T-O braces in enhancing seismic performance. However, the frames with T-O braces had a resultant lower lateral stiffness - suggesting that T-O braces of sufficient stiffness could be used to garner similar responses offered by T-C braces.</p> / Master of Applied Science (MASc)

<p>Southern Ontario residents are faced with many challenging decisions when growing their own food. The intention of my research is to help these urban residents plan their garden plot in order to yield food for their own use. The form of this research will be a thesis incorporating a decision support system (DSS). This DSS is intended to take in and determine relevant site characteristics (latitude, sun/shade conditions) and use this information to help the user choose a variety of vegetables and herbs. Users will have the option of making a simplified model of their property and nearby structures for shade analysis, and with the results select an appropriate area(s) of their land. This DSS will give the user the freedom to pick vegetables based on conditions and preferences and give graphical and tabular output of the garden layout and details.</p> <p>The objectives of this thesis is to present the why, what, who, where, and how of going beyond local food production for urban consumption to urban citizens growing their own food for themselves. This food can be consumed but also used as a currency with which to barter for other yard produce from neighbours or community members. One could imagine having a bartering relationship with a neighbour or having a weekly or monthly food market to facilitate bartering. This DSS is intended to be one of the building blocks of a food network DSS, which would be used to increase the efficiency of sharing food produced in urban residential gardens (that have been planned using the following DSS prototype).</p> / Master of Applied Science (MASc)

<p>To obtain a better understanding of groundwater contamination, experiments of biocolloid and colloid transport in single, saturated fractures are conducted to have research in contaminants transport in fractured media. Hydraulic tests and solute tracer tests were conducted to characterize fractures. Due to the relatively large volume in the recirculation system, a back-calculation is employed in the analysis of tracer tests.</p> <p>E. coli RS-2GFP tracer tests were conducted on three fractures at specific discharges of 0.1, 1 and 10 cm/min. With higher specific discharges, the percent recovery is higher in F2 and F3, as well as the colloid experiments, which is likely due to higher specific discharges providing biocolloids less opportunity to attach to the fracture walls. But this did not occur in F1, which is likely due to the smaller aperture size.</p> <p>Comparing the synthetic replicas with real fractures in similar specific discharges, recovery of biocolloid was smaller than colloid. In colloid tracer tests, higher recovery appeared in the fractures with larger aperture field, but this is not clearly seen in biocolloid tracer tests. These indicate that the biological properties of bacteria, and the difference of fracture region and the tortuosity influence the transport.</p> / Master of Applied Science (MASc)